Dependence of the climate prediction skill on spatio-temporal scales: internal versus radiatively-forced contribution
Volpi, D. ; Doblas-Reyes, F. J. ; García-Serrano, J. ; Guemas, Virginie
This article aims at quantifying the improvement in climate prediction skill as a function of temporal (from monthly to decadal) and spatial scales (from grid-point to global) when initializing a perturbed parameter ensemble of the Hadley Centre Climate Model. The focus is on near surface temperature and precipitation in the tropical band, the Northern and Southern hemispheres. For temperature, the forecast system reproduces the dominant impact of the external forcing at global spatial scale and at decadal time scales. There are significant improvements with initialization for the first 40 forecast months in the global and tropical domains. In the Northern (Southern) hemisphere, the initialization increases the skill in the first 12 (20) months on regional but not hemispheric scales. The initialization has a stronger impact in the model variants with a weaker global-mean temperature trend. For precipitation, the initialization corrects the negative correlation found at global and tropical scales.
Accès à la notice sur le site du portail documentaire de Météo-France